Crumpling mechanism for creating dunnage

Abstract

A dunnage crumpling apparatus is provided having first and second entry-side crumpling members and first and second exit-side crumpling members. The first and second entry-side crumpling members define an entry therebetween. The first and second exit-side crumpling members define an exit therebetween that is disposed along the longitudinal path downstream of the entry. A crumpling zone being defined between the entry and exit. The first entry-side crumpling member is configured for moving at an first rate and is associated with the second entry-side crumpling member for moving sheet material through the entry in a first direction along a longitudinal path at an entry rate. The first exit-side crumpling member is configured for moving at an second rate and is associated with the second exit-side crumpling member for moving the sheet material through the exit in the first direction along the path at a exit rate that is slower than the entry rate to crumple the sheet material for producing dunnage. The entry and exit-side crumpling members are displaced laterally along the path with respect to each other to cause shearing of the sheet within the crumpling zone.

What is claimed is: 
     
       1. A method of producing a transversely crumpled dunnage unit, comprising:
 operating a first set of entry-side crumpling members engaged with opposite faces of a stock material at a first entry-engagement location on a first transverse side of a first transverse region of the stock material, to advance the stock material on the first transverse side along a path at an entry rate; and 
 operating a first set of exit-side crumpling members engaged with the opposite faces of the stock material at a first exit-engagement location downstream of the first set of entry-side crumpling members and on a second transverse side of the first transverse region of the stock material transversely opposite from the first transverse side, such that the first set of entry-side crumpling members and the first set of exit-side crumpling members define a crumpling zone therebetween in the first transverse region, to move the stock material at an exit rate that is slower than the entry rate, thereby retarding the advancing stock material on the second transverse side and causing a shearing within the stock material in the crumpling zone, which shearing creases the stock material in the first transverse region, which creasing forms a first crimped region along the first transverse region that includes interlocked compressed folds, 
 wherein the first set of entry-side crumpling members and the first set of exit-side crumpling members are offset laterally to define a space laterally adjacent to the exit-side crumpling members directly downstream along the path from the entry-side crumpling members and to define another space laterally adjacent the entry-side crumpling members directly upstream along the path from the exit-side crumpling members, and 
 wherein a size of the space is selected to cause sufficient shearing to increase creasing while preventing tearing of the stock material. 
 
     
     
       2. The method of  claim 1 , wherein the shearing of the stock material is such that the crimped region has a criss-crossing pattern. 
     
     
       3. The method of  claim 1 , wherein:
 the first entry-side and exit-side crumpling members comprise rollers, and 
 the first entry-side crumpling rollers overlap the first exit-side crumpling rollers in a longitudinal direction that extends along the path. 
 
     
     
       4. The method of  claim 1 , the method further comprising:
 operating a second set of entry-side crumpling members engaged with the opposite faces of the stock material at a second entry-engagement location on a first transverse side of a second transverse region of the stock material that is adjacent to the first transverse region of the stock material to advance the stock material on the first transverse side of the second transverse region along a path at the entry rate; and 
 operating a second set of exit-side crumpling members engaged with the opposite faces of the stock material at a second exit-engagement location downstream of the second set of entry-side crumpling members and on a second transverse side of the second transverse region of the stock material transversely opposite from the first transverse side, such that the second set of entry-side crumpling members and the second set of exit-side crumpling members define a second crumpling zone therebetween in the second transverse region, to move the stock material at an exit rate that is slower than the entry rate, thereby retarding the advancing stock material on the second transverse side and causing a shearing of the stock material within the second crumpling zone, which shearing creases the stock material in the first transverse region, which creasing forms a second crimped region along the second transverse region that includes interlocked compressed folds. 
 
     
     
       5. The method of  claim 4 , wherein the shearing of the stock material is such that both of the crimped regions have criss-crossing patterns. 
     
     
       6. The method of  claim 4 , wherein the second set of entry-side crumpling members are offset laterally with respect to the second set of exit-side crumpling members to define a space within the second crumpling zone that is laterally adjacent the second set of exit-side crumpling members at a location directly downstream along the path from the entry-side members, and to define another space within the second crumpling zone that is laterally adjacent the second set of entry-side crumpling members at a location directly upstream along the path from the second set of exit-side crumpling members, to cause shearing of the stock material in the second transverse region of the stock material within the second crumpling zone. 
     
     
       7. The method of  claim 4 , wherein the first entry-side and first exit-side crumpling members and the second entry-side and second exit-side crumpling members are operated to form common compression folds having a lower frequency than the compressed folds formed in the first and second crimped regions, which common folds are locked in by the first and second crimped regions and are disposed transversely between the first and second transverse regions of the stock material. 
     
     
       8. The method of  claim 1 , wherein the shearing crumples the stock material along axes that are non-orthogonal with respect to the longitudinal path. 
     
     
       9. The method of  claim 8 , wherein the shearing crumples the stock material along axes that are up to 10 degrees to 20 degrees with respect to the longitudinal path. 
     
     
       10. The method of  claim 1 , wherein the stock material is comprised of a roll of paper. 
     
     
       11. The method of  claim 1 , wherein the stock material is comprised of a stack of paper. 
     
     
       12. The method of  claim 11 , wherein the stack is formed of a long sheet of material. 
     
     
       13. The method of  claim 11 , wherein the stack is formed of a plurality of attached sheets. 
     
     
       14. The method of  claim 11 , wherein the stack of paper is formed of a plurality of separate individual sheets of paper. 
     
     
       15. The method of  claim 1 , wherein the stock material is an elongated sheet material provided in a roll or as a stack of a plurality of attached sheets. 
     
     
       16. The method of  claim 1 , wherein the first set of entry-side crumpling members are disposed completely out of alignment with respect to the first set of exit-side crumpling members downstream along the path such that the first set of entry-side crumpling members move the sheet material at a first location and the first set of exit-side crumpling members cause resistance against the sheet material at a location different from the first location. 
     
     
       17. The method of  claim 1 , wherein:
 the first set of exit-side crumpling members includes:
 a first exit-side crumpling member, and 
 a second exit-side crumpling member; and 
 
 the first set of entry-side crumpling members includes:
 a first entry-side crumpling member, and 
 a second entry-side crumpling member. 
 
 
     
     
       18. The method of  claim 17 , wherein each of the first and second exit-side crumpling members has a surface, the surface of the first exit-side crumpling member in substantially continuous abutment against the surface of the second exit-side crumpling member to pinch the sheet material in the exit throughout rotation of the exit-side members. 
     
     
       19. The method of  claim 1 , wherein the crumpling zone is generally defined by the entry and exit-side crumpling members to have a generally diamond shaped in a lateral-view cross-section, and the crumpling zone comprising an entry-zone, a feed-zone, and exit-zone. 
     
     
       20. The method of  claim 1 , wherein the first set of entry-side crumpling members and the first set of exit-side crumpling members are spaced laterally from each other sufficiently to allow the shearing of the sheet in the crumpling zone. 
     
     
       21. The method of  claim 20 , wherein the first set of entry-side crumpling members and the first set of exit-side crumpling members are spaced laterally from each other sufficiently to prevent tearing of the stock material in the crumpling zone. 
     
     
       22. The method of  claim 1 , wherein the first entry-side and first exit-side crumpling members are operated to form common compression folds having a lower frequency than the compressed folds formed in the crimped region, which common folds are locked in by the first crimped region. 
     
     
       23. The method of  claim 1 , wherein the first set of exit-side crumpling members are operated to avoid retarding the stock material in the first transverse region directly downstream of the entry-side crumpling members, transversely adjacent from the exit-side crumpling members. 
     
     
       24. The method of  claim 1 , wherein the lateral offset between the entry and exit-side crumpling members is such that the stock material is not impeded by the exit-side crumpling members in the space laterally adjacent to the exit-side crumpling members directly downstream along the path from the entry-side crumpling members.